The leading cause of neck pain arises from rupture or degeneration of cervical intervertebral discs. Pain in the upper extremities may be caused by compression of spinal nerve roots by a bulging disc, while neck pain may be caused by collapse of the disc and by the adverse effects of bearing weight through a damaged, unstable vertebral joint. One conventional method of managing these problems is to remove the problematic disc and replace it with a prosthetic disc that allows for the natural motion between the adjacent vertebrae (“a motion disc”).
U.S. Pat. No. 6,113,637 (“Gill”) discloses a motion disc having a ball and socket articulation, wherein the trough of the socket has a flat portion. The ball and socket geometry provides pivotal motion while the flat portion of the trough allows the ball to slide, thereby providing some translation motion. Gill further discloses a method of linering the motion disc whereby an linering device engages the ball and socket components to fix the spatial relationship between the components. The components are then linered into the disc space in this fixed spatial relationship. Therefore, during the entire insertion procedure, the original spatial relationship may be maintained.